Cross arm supporting gain for attachment to transmission line poles



Dec. 15, 1953 2,662,714

K. c. JENNE CROSS ARM SUPPORTING GAIN FOR ATTACHMENT TO TRANSMISSIONLINE POLES Filed June 11, 1949 2 Sheets-Sheet l mumii: t. 3

lllln 3nvenior KENNETH B. U'ENNE. (7 4, MW-

K. C. JENNE Dec. 15, 1953 CROSS ARM SUPPORTING GAIN FOR ATTACHMENT TOTRANSMISSION LINE POLES 2 Sheets-Sheet 2 Filed June 11, 1949 lsnvenforKENNUH E. LJEN E.

Gttorneg Patented Dec. 15, 1953 UNITED STATES PATENT ()FFICE oRoss ARM--SUPPORTING- GAIN FOR A1:-

TACHMENT 'ro TRANSMISSION LINE POLES keiineth JienneLB i'anford, Conn;assignon Malleable t e Fittings Cpmpany Bil-aurora,

Gonn a corporation of Connecticut J i iilibanir Iune 11, 1949, sea No.92%,574

4 Claims.

The present inventionrelates to a cross arm supporting gain amusemen topoles suchas transmission line poles, and particularlj a gain for thesupport of the cross arm or ti-frame structure consisting of twour'ri'ght poles supported at spaced points in thegrou'nd and a horizontally disposed cross" connected to the uprights near their upperends, the cross arm usual- 1y projecting outwardly beyond each of theuprights. An object of the invention is to provide again of thischaracter, especially adapted to effectually support a cross arm ofround or circular cross section and usuall'y taperedbetween its ends,that is), a cross aifm con isting of a length of unsquaredtimber' fromwhich thebark has been removed) but is otherwise in its natural state,as distinguished from ,a' souared cross arm formed from a length oftimber having slabs re: moved from its four sides; Ih cross arm may, beof equal diameterthrjoughout its length or may be tapered from thecenter toward each end, these shapes being produced by turning, V I

The round cross rm has a na b w gi n: tages over the squared crossarm,aside from the fact that the expense of trimming and handiing in themill is eliminated. The roundcross arm has greater inherent strength, and when fastened by bolts through its diametric center its maximium loadsupporting potentialities may be fully realized. t V t The conventionaltype" of cross arm gain here tofore in use has'beendesighedespeciallyfor the support of a squared cross arm, being providedwith a right-angle step in'which one corner of the cross arm is seated,a hole b e'ing provided above the step for receiving the through-bolti'or at taching the gain and crossarm to the upright. In using this typeof gain for the support of around tapered cross arm it is not possible,because of the variation of the diameter of the crossarm, to

uniformly fasten the cross arm by through bolts extending through itsdiametr'ic center. Further? more, the step supportis only engaged at itsouter edge by the cross 'armgso that various diameters of cross armswill not be uniformly supported Also it is impractical to drill theholes in the ,Qross arm to receive thethroughe-bolts before its ac tualinstallation, asthe position of these holes will vary, depending uponthe particular diameter Prbduced i t? sins e tand rd d sizesand whensadapted to accommodate all diameters t e; a-msgwa'ma the iatgeemamtniyage such range being for instance between fi and 12 /2 inches indiameterl.v it is further proposed to previe gain in which the through--bolt may be engaged through the diametric centeroi the cross arm, andin which" the po'int of support of the .cross-arm on th'e gain is alwaysin substan: tially thesame remnants the. center of gravitv of thecross'ar'm regardlessoi its diameter. A furtherobject is to provide aorossarm sup; rtin gain which willpe'rmit the uprightpoles to be rockedor tilted toa' considerable degree; without causing the gain to bedisplaced. upon. the Vertical pole, whileat'the same time providingadequate support for heprtssarm; With the above and other objects inview, an embodiment. of the, invention is shown ,in the aeeompany'ingdrawingsv and this embodiment will he hereinafter more anydeseribedflwith reference thereto, and the in've'ntion will be finallypointed in the claims.

In the ra ings; l t

embodiment of the invention. Fig. 2 is a front elevation.

3 is alrear elevationr Fig. 4 1st ap ear/raw.

,F -6' i e ieie r ee l a ion eri" iii vertical section, showing anH-fra1ne structure wherein ata'p e redcross arm is supported on two bish }p01es. v p .Pie- {Ri a e e e atip i t e it? s b diagrammaticallvJoy dot-and-dash lines ere, lative posit'ions of crossarrnsof sma lland'isig'e diameterssupported:upoii the gainL Peri he th rela ir e' sofi i r arm and gainiinthe oaseof {the upright pole being tilted orrocked over from its normal vertical i fi V. i 9 is a side elevation,onare uced sca showing the" gain-oi the invention employed with--external bolt means securing thec'ros s arm to the pole .Li C; .7 ::i tFig. '10 is a sectional view along the line lfl l'0 er fie .i ifil r wllt r s amthrip n ga n a qer' n t he i us' aie exem, plary embodiment oftheinvention, comprises a, one-piece, body,, indicated generally. as1.0, and preferably, in the form ofra malleable iron. cast= ing,consisting of a forward wall having an upper fiat-surfaced vertical wallportion H, a downwardly and outwardly curved wall portion l2, and adownwardly and outwardly inclined wall portion I3, the vertical andinclined wall portions El and [3 being tangential to the curved surfacel2. The forward end of the inclined wall portion l3 forms a point withthe forward end of the lower downwardly and inwardly inclined wallportion M, the inner end of which is curved downwardly at its lowerside, as at I5, to provide a gradually increasing thickness terminatingin a concave heel or bearing surface [6 adapted to substantially conformto the curvature of the upright pole. A series of spur teeth H areprovided across the heel surface for digging into the pole to resistdownward sliding movement of the gain thereon. Side walls l8l8 enclosethe sides of the body member and have vertically disposed rearwardsurfaces l9l9 which constitute vertical ribs for engagement with thesurface of the upright pole. A vertically disposed slot for receivingthe through-bolt is provided in the upper vertical wall portion II.

In practice the radius of the curved wall [2 is approximately equal tothe radius of the smallest size cross arm to be supported, the tangentwall portion l3 being at an angle of approximately 120 with the uppervertical wall portion II. It has been found that this angle allows alarger range of cross arm sizes for a given length of the slot 20, andconsequently a shorter over-all height to the gain. Also itautomatically keeps the point of support approximately the same distancefrom the center of gravity throughout the full range and gives a fiatsurfacenot an edgefor the cross arm to rest The gain is assembled withthe cross arm and upright poles as follows:

While the cross arm 2| is on the ground it is drilled at the desiredmounting points with horizontal diametric bolt-receiving holes 22 andthereupon the gains are attached to the pole in relation to each of thedrilled holes. In practice each gain is placed against the cross arm sothat the vertical wall portion II is at a right angle to the axis of thehole 22 with the slot 20 in line with the hole. The inclined supportingsurface :3 is then brought into contact with the surface of the crossarm and the gain is fastened to the cross arm by nails 23 engagedthrough holes 24 provided in the gain. The cross arm together with thegains secured thereto is then mounted upon the upright poles 2525, eachof which is provided with a horizontally disposed throughbolt 26 engagedin a hole 21, by engaging the through-bolts through the slots 20 of thegains and through the holes 22 of the cross arms. A curved washer 25 isengaged upon the throughbolt at the rearward side of each upright poleand is secured by a nut 29 screwed upon the rearward end of thethrough-bolt. A curved washer 39 is engaged upon the forward end of eachthrough-bolt against the forward side of the cross arm and is secured bya nut 3|. Tightening of the nuts 29 and 3| forces the cross arm inwardlyagainst the gain and forces the gain tightly against the forward surfaceof the upright pole, the combined tightening action and the weight ofthe cross arm causing the inner edges of the side walls to engage firmlyagainst the pole and causing the spur teeth I! of the heel surface Hi tobite into the upright pole.

As shown clearly in Fig. 6, a tapered cross arm is supported upon twoupright poles in an H-frame structure. The smaller diameter end of thecross arm has its horizontal diametric center line in horizontal linewith the horizontal diametric center line of the larger diameter end ofthe cross arm, the gain supporting the smaller end being mounted higherthan the gain supporting the larger end, so that the through-boltengaged with the larger end is at a higher point in the slot 20 of itssupporting gain than the through-bolt of the smaller end. Thus,irrespective of the diameter of the cross arm, it is firmly engaged withthe gain at two surface areas, namely along the vertical wall portion IIand along the downwardly and outwardly inclined wall portion l3. Asshown in Fig. 7, a large diameter cross arm will be supported upon thegain so that the through-bolt extending through its horizontal diametriccenter is near the top of the slot 20 and its point of engagement withthe surface of the inclined Wall i3 is near the outer end of thissurface, while the small diameter cross arm has its through bolt engagednear the bottom of the slot 20 and its point of engagement with thesurface of the inclined wall I 3 relatively higher up on this surfacethan the larger diameter cross arm. These points of engagement aresubstantially proportional for the complete range of sizes, being insubstantially the same relation to the center of gravity of the crossarm. The comparative relation is shown by the triangles L and Sconnecting the center of gravity and the contact points with the gain ofthe large and small diameter cross arms.

Assuming the center of gravity is through the vertical diametric centerline of the cross arm and at a point outwardly of the point ofengagement of the cross arm with the wall portion l3, a vertical load onthe cross arm results in a rotatmg force applied to the gain, causingthe heel of the gain to press firmly against the upright pole withincreasing force as the load is increased, as distinguished from asliding or shearing force that would result in the case of supportingthe load in vertical line with the center of gravity or at a pointoutwardly of the center of gravity. Consequently a relatively great loadmay be imposed upon the cross arm without bending of the through-boltand without causing the gain to be forced downwardly upon the uprightpole. The larger the diameter of the cross arm the greater is thedistance from the pole at which the weight of the cross arm is imposedupon the gain so that the resulting force tends only to increase thepressure at the heel of the gain. Assuming that there is sufficientbearing area at the heel of the gain and that the washers 2i and 29 areof adequate size, there will be no appreciable difference in theperformance of the gain between the smaller and larger diameter crossarms. The same effective support will also be provided in the case ofcross arms which may be of oval or out of round cross-section, or whichmay have flat, depressed or projected surfaces. In each such case onepoint will firmly engage the vertical surface H and another point willfirmly engage the surface [3.

Pole installations are sometimes subject to storm or other conditionswhich may cause them to tilt or rock over. The gain of the invention isdesigned to minimize the damage that may result from these conditions.As shown in Fig. 8 the gain will remain in aligned position upon theupright pole when the latter is tilted, while the cross arm remainshorizontal, the through bolt being forced upwardly in the slot 20 as thesupinstallation where it is porting surface l3 assumes an angle to thecross arm. Consequently the danger of breaking the cross arm or the gainis minimized, and adequate bearing of the heel of the gain against thepole is maintained.

In Figs. 9 and 10 the gain is shown in a pole desired to eliminatedrilled holes through the cross arm and vertical pole. The gain i0 isfirst fastened to the cross arm 2| by nails 23 before mounting on thevertical pole 25, so that the cross arm is in engagement with thevertical surface 1 I at its horizontal diametric point and is in contactwith the inclined surface 13 at a point substantially centrally of thevertical surface [0 and the center axis of the cross arm 2!, as shown inthe diagrammatic illustration in Fig. 7. Pairs of substantiallysemi-circular clamps 32 are respectively engaged about the cross arm 2!at each side of the gain and about the vertical pole 25 above and belowthe gain, these clamps being provided with end flanges 33 connected bybolts 34. The clamps are each preferably formed of two quarter-roundparts provided at their inner ends with flanges 35 connected by bolts36, so that the clamps may be adjusted to different diameter poles. Theclamps are also provided with nail receiving holes 31, so that they maybe fixed upon the cross arm and vertical pole by nails 38 to preventrelative turning movement. As the gain is employed in this type ofinstallation without the through bolt 26, the slot opening 20 maybeeliminated, but for standardization purposes it is preferably includedso that the same gain may be used in either type of installation.

I have illustrated and described a preferred and satisfactory embodimentof the invention, but it will be understood that changes may be madetherein within the spirit and scope thereof as defined in the appendedclaims.

What is claimed is:

1. A gain, for use between the upright face of a vertical pole and theinner and lower sides of a horizontal cross arm of substantiallycircular cross-section to oppose the downward and inward force imposedby the cross arm, comprising a body member having a pole engagingrearward side having generally vertical pole engaging bearing surfaces,and a forward side including an upper generally vertical wall portionsubstantially parallel to said pole engaging bearing surfaces and ofsubstantial length to constitute a vertically ranging cross arm engagingsurface, a generally inclined wall portion extending downwardly andforwardly from said upper wall portion in downwardly divergent-relationto said pole engaging bearing surfaces and of substantial length toconstitute a downwardly and forwardly ranging cross arm engagingsurface, the lower end of said inclined wall portion being the forwardterminal of the body member, and a bottom wall portion extendinginwardly from the lower end of said inclined Wall portion and having arearward end surface constituting a pole-engaging heel.

2. The invention as defined in claim 1, further characterized in thatsaid upper vertical wall surface is provided with a through boltreceiving vertical slot.

3. The invention as defined in claim 1, further characterized in thatsaid pole-engaging heel has projecting pole-engaging spur teeth.

*1. A gain, for use between the upright face of a vertical pole and theinner and lower sides of a horizontal cross arm of substantiallycircular cross-section to oppose the downward and inward force imposedby the cross arm, comprising a body member having a pole engagingrearward side having generally vertical pole engaging bearing surfaces,and a forward side including an upper generally vertical wall portionsubstantially parallel to said pole engaging bearing surfaces and ofsubstantial length to constitute a vertically ranging cross arm engagingmember, a generally inclined wall portion extending downwardly andforwardly from said upper wall portion in downwardly divergent relationto said pole engaging bearing surfaces and of substantial length toconstitute a downwardly and forwardly ranging cross arm engagingsurface, the lower end of said inclined wall portion being the forwardterminal of the body member, and a bottom wall portion extendingdownwardly and inwardly from the lower end of said inclined wall portionand having a rearward end surface constituting a pole-engaging heel.

KENNETH C. JENNE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 840,009 Peirce Jan. 1, 1907 882,835 McGillivray Mar. 24, 1908900,545 Humiston Oct, 6, 1908 900,663 Callane Oct. 6, 1908 1,260,951Baker Mar. 26, 1918 1,583,409 Marquart May 4, 1926 1,740,769 Faber Dec.24, 1929 2,201,138 Hyde May 21, 1940 2,606,952 Cofer et al Aug. 12, 1952FOREIGN PATENTS Number Country Date 425,376 Germany Feb. 18, 1926

